The present invention generally relates to films used in manufacture of semiconductor devices, especially to nitride films and oxide films.
In order to improve drive current in complementary metal oxide semiconductor (CMOS) devices, stressed films have been used either as spacers or middle-of-the-line (MOL) liners (also known as pre-metal dielectric (PMD) liners). Deposition regimes that result in either highly tensile or highly compressive nitride films are well known (e.g., rapid thermal chemical vapor deposition (RTCVD), plasma enhanced chemical vapor deposition (PECVD), high density plasma (HDP) using silicon (Si) precursor such as silane (SiH4), di chloro silane (DCS), Disilane, Hexachlorodisilane, bis-tertiary butyl amino silane (BTBAS), and ammonia (NH3)). However, within a given deposition regime it only has been possible to modulate the stress within a small range. It has been very difficult to modulate the stress to a large extent without comprising the film quality.
Also, there has been a growing need for nitride/oxide films deposited at a lower temperature for MOL driven by the introduction of nitride silicon (NiSi) processes. Many low temperature precursors have been investigated, and none has turned out to be ideal.
Typically, in an LPCVD furnace, DCS and NH3 are used for depositing silicon nitride film at temperatures of 700 C and higher.